/*
 * @(#)PolicyCombinerElement.java
 *
 * Copyright 2005 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistribution of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 * 
 *   2. Redistribution in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
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 *
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 */

package org.wso2.balana.combine;

import org.wso2.balana.AbstractPolicy;
import org.wso2.balana.Indenter;
import org.wso2.balana.Policy;
import org.wso2.balana.PolicyReference;
import org.wso2.balana.PolicySet;

import java.io.OutputStream;
import java.io.PrintStream;

import java.util.Iterator;
import java.util.List;

/**
 * Specific version of <code>CombinerElement</code> used for policy combining.
 * 
 * @since 2.0
 * @author Seth Proctor
 */
public class PolicyCombinerElement extends CombinerElement {

	/**
	 * Constructor that only takes an <code>AbstractPolicy</code. No parameters
	 * are associated with this <code>AbstractPolicy</code> when combining.
	 * 
	 * @param policy
	 *            an <code>AbstractPolicy</code> to use in combining
	 */
	public PolicyCombinerElement(AbstractPolicy policy) {
		super(policy);
	}

	/**
	 * Constructor that takes both the <code>AbstractPolicy</code> to combine
	 * and its associated combiner parameters.
	 * 
	 * @param policy
	 *            an <code>AbstractPolicy</code> to use in combining
	 * @param parameters
	 *            a (possibly empty) non-null <code>List</code> of
	 *            <code>CombinerParameter<code>s provided for general
	 *                   use (for all pre-2.0 policies this must be empty)
	 */
	public PolicyCombinerElement(AbstractPolicy policy, List parameters) {
		super(policy, parameters);
	}

	/**
	 * Returns the <code>AbstractPolicy</code> in this element.
	 * 
	 * @return the element's <code>AbstractPolicy</code>
	 */
	public AbstractPolicy getPolicy() {
		return (AbstractPolicy) (getElement());
	}

	/**
	 * Encodes this element's <code>AbstractPolicy</code> and parameters into
	 * their XML representation and writes this encoding to the given
	 * <code>OutputStream</code> with indentation.
	 * 
	 * @param output
	 *            a stream into which the XML-encoded data is written
	 * @param indenter
	 *            an object that creates indentation strings
	 */
	public void encode(OutputStream output, Indenter indenter) {
		if (!getParameters().isEmpty()) {
			AbstractPolicy policy = getPolicy();

			// should get folded into the AbstractPolicy API?
			if (policy instanceof Policy) {
				encodeParamaters(output, indenter, "Policy", policy.getId()
						.toString());
			} else if (policy instanceof PolicySet) {
				encodeParamaters(output, indenter, "PolicySet", policy.getId()
						.toString());
			} else {
				PolicyReference ref = (PolicyReference) policy;
				if (ref.getReferenceType() == PolicyReference.POLICY_REFERENCE)
					encodeParamaters(output, indenter, "Policy", ref
							.getReference().toString());
				else
					encodeParamaters(output, indenter, "PolicySet", ref
							.getReference().toString());
			}
		}

		getPolicy().encode(output, indenter);
	}

	/**
	 * Private helper that encodes the parameters based on the type
	 */
	private void encodeParamaters(OutputStream output, Indenter indenter,
			String prefix, String id) {
		PrintStream out = new PrintStream(output);
		String indent = indenter.makeString();
		Iterator it = getParameters().iterator();

		out.println(indent + "<" + prefix + "CombinerParameters " + prefix
				+ "IdRef=\"" + id + "\">");
		indenter.in();

		while (it.hasNext()) {
			CombinerParameter param = (CombinerParameter) (it.next());
			param.encode(output, indenter);
		}

		out.println(indent + "</" + prefix + "CombinerParameters>");
		indenter.out();
	}

}
